We have developed a custom two-photon imaging system in NIDA IRP BRC building. The new custom two-photon system, combined with GRIN lens imaging, allows deep brain imaging in live animals with cellular and subcellualr resolution, and is currently been shared by entire NIDA IRP community. We have also developed a miniScope system that allows imaging of neuronal circuit function with single neuron resolution in freely moving animals in deep brain regions. The miniScope has been applied to freely moving mice imaging in NIDA IRP, and are currently been applied to in vivo imaging in freely moving rats. We are also developing a image relay fiber based optical imaging system that could be combined with fMRI imaging, this new imaging technique will be apply to NIDA IRP research with the euro imaging branch in the near future, allowing detailed examination of fMRI BOLD signal and neuronal circuit activity in the same animal simultaneously.